56 A SEARCH IN SECRET EGYPT the Pyramid has proved the excellence and ingenuity of this architectural plan. One curious thing which Vyse found was the first and only series of hieroglyphs which have ever been discovered inside the Pyramid since the inscribed outer casing was stripped off. These were the quarry-masons' marks on the rough faces of the stones in the five construction chambers. Among these marks were the cartouches, or oval-framed picture-writing, of three royal names—Khufu, Khnem Khufu and Khnem, They were not inscribed, but drawn in red paint, as masons' marks generally were in ancient Egypt. Egyptologists could only hazard guesses at the meaning of Khnem, and they had never heard of any Egyptian king bearing that name. They could give no proper explanation of the presence of this name. But they knew very well who Khufu was: that Fourth Dynasty Pharaoh to whom the later Greek historians unfortunately Attached the name of Cheops, This discovery of Vyse's finally settled the date of the Pyramid's building for them; Khufu had erected it and none else. But nowhere in the Pyramid has Khufu's mummy ever been found.